Endometriosis is linked to an increased risk of certain types of ovarian cancer, say international researchers.
In a study of 23,000 women with invasive ovarian cancer from the USA, Europe and Australia, self-reported endometriosis symptoms were obtained from a questionnaire.
Of the women diagnosed with clear cell invasive ovarian cancer, a fifth reported endometriosis symptoms, compared with 6% of controls without the disease.
A similar relationship was seen for women with endometrioid and low-grade serous invasive ovarian cancer, with 14% and 9% reporting endometriosis symptoms.
Study lead Professor Celeste Leigh Pearce, assistant professor in preventive medicine at the University of Southern California, USA, said: ‘Endometriosis should be thought of as a precursor lesion for clear cell and endometrioid cancers.’